Pharmacology for Dentistry

Antifungal Agents 345

It is not effective against fungi causing
deep/systemic infection.

It interferes with mitosis and also
causes abnormal metaphase configura-
tions. Griseofulvin gets deposited in kera-
tin and persists for weeks. As it is fungi-
static the newly formed keratin is not in-
vaded by the fungus but fungus persists in
already infected keratin, till it is shed off.

Oral absorption is irregular. It is largely
metabolised by methylation and excreted
in urine. It is ineffective topically.

Adverse effects include nausea, epigas-
tric distress, vomiting, headache, peripheral
neuritis, skin rash, photosensitivity, drowsi-
ness and transient leucopenia. It can cause
disulfiram like reaction.

It is indicated in fungal infections of
skin, scalp and nails, tinea of hand and
beard and athlete’s foot.

PIMARICIN

It is obtained from Streptomyces notalensis
and it is found effective against Trichophyton
violaceum, Trichomonas vaginalis and
Aspergillus fumigatus. It is used as eye ointment
in keratitis due to Fusarium and Cephalosporium
and as an inhalation in bronchopulmonary
aspergillosis and candidiasis.

HAMYCIN

It is obtained from Streptomyces pimprina
and effective against blastomycosis,
cryptococcosis, vaginal and cutaneous
candidiasis, Trichomonas vaginitis and
Aspergillus otomycosis.

Adverse effects include diarrhoea,
eosinophilia, nephrotoxicity and rise in
SGOT levels after oral administration in the
treatment of blastomycosis in man.

ANTIMETABOLITES

FLUCYTOSINE

It is a synthetic fluorinated pyrimidine

anti-metabolite which acts by its conversion

to anti-metabolite 5-fluorouracil which

inhibit DNA synthesis.

It is effective against Cryptococcus

neoformans and some Candida strains and

dermatiaceous moulds which cause

chromoblastomycosis.

Adverse effects include anaemia,

leukopenia, thrombocytopenia, diarrhoea,

GIT disturbances and liver dysfunction.

It is mainly used as an adjuvant drug

to amphotericin.

IMIDAZOLES & TRIAZOLES

CLOTRIMAZOLE

Clotrimazole, is an imidazole derivative

and has a broad antimycotic spectrum of

action in vivo, which includes dermato-

phytes, yeasts, moulds etc.

Clotrimazole acts against fungi by in-

hibiting ergosterol synthesis. Inhibition

of ergosterol synthesis leads to structural

and functional impairment of the cytoplas-

mic membrane.

In addition, it also acts on Trichomonas

vaginalis, gram positive microorganisms

(streptococci/staphylococci) and gram

negative microorganisms (Bacteroides/

Gardnerella vaginalis).

It is useful as topical application. It is

indicated in infections of the genital region

(vaginitis) caused by fungi (mostly Candida)

and superinfections caused by clotrimazole

sensitive bacteria; infectious leucorrhoea

caused by yeast fungi.